The invention relates to a wheelchair braking system. More particularly, the invention relates to a system for automatically preventing the wheels of a wheelchair from moving when the passenger is not fully seated in the wheelchair, thus preventing the wheelchair from moving suddenly while the passenger is in the process of sitting down or getting up from the wheelchair.
Standard wheelchairs have two large wheels which are attached on the sides of the wheelchair. These wheels are typically mounted in a manner which maximizes freedom of movement, to facilitate low effort mobility for the passenger seated in the wheelchair. However, having freely moving wheels is not always advantageous. When the passenger is getting up from the wheelchair, or sitting down, it is highly desirable that the wheelchair provide some degree of "sure footing" for the passenger. The passenger relies on the wheelchair to balance themselves while getting up and sitting down.
Frequently, the wheelchair does not provide the needed balance, but instead rolls backward just as the passenger shifts their weight toward the wheelchair. Thus, the end result is typically a fall. The fall can cause severe injury, especially if the passenger hits their head on the chair on the way down. Often the passenger is using the wheelchair because of an injury. Thus, a fall therefrom can aggravate existing injuries, prevent them from healing correctly, or even cause new injuries.
To prevent such mishaps, some wheelchairs have a manual brake provided. U.S. Pat. No. 5,379,866 to Pearce et al. discloses a light-weight wheel assembly and static brake for wheelchairs. This manual brake allows the passenger to lock the wheels before sitting down or getting up from the wheelchair. However, the manual brake is only effective in preventing injury if the passenger remembers to set it. Further, many people who use wheelchairs suffer from diminished mental capacity. These people often forget to set the brake, and then fall when they try to get up from the wheelchair.
U.S. Pat. No. 5,358,266 to Roth et al. discloses a wheelchair electric brake and pedal safety kit. A wheelchair braking system is disclosed which has an electric switch mounted within the seat for sensing the weight of the passenger, and a brake that is operated thereby. Unfortunately, the device in Roth is electrically operated. Thus, it requires that the user maintain a charged battery power source in order for the brake to continue to operate properly.
U.S. Pat. No. 5,203,433 discloses an automatic braking wheelchair, which employs an arm that is directly linked between the seat and the wheel, for locking the wheel when the passenger rises from the seat. U.S. Pat. Nos. 4,733,755 to Manning and 4,623,043 to Babilas both disclose devices which seek to automatically lock the wheels when the passenger is exiting the wheelchair.
While these units may be suitable for the particular purpose employed, or for general use, they would not be as suitable for the purposes of the present invention as disclosed hereafter.